Association of handgrip strength asymmetry and weakness with functional disability among middle-aged and older adults in China

Background Little is known about the association of handgrip strength (HGS) asymmetry with functional disability in China. We aimed to examine the individual and combined association of HGS asymmetry and weakness with functional disability among middle-aged and older Chinese adults. Methods We included participants aged ≥45 years from two waves of the China Health and Retirement Longitudinal Study (2011 and 2015). HGS weakness was defined as the maximal HGS<28 kg for men and <18 kg for women. HGS asymmetry was measured by dividing the maximal nondominant HGS (kg) by the maximal dominant HGS (kg), with the value <0.90 or >1.10 considered as asymmetry. Functional disability was assessed by activities of daily living (ADL) and instrumental activities of daily living (IADL) and was defined as encountering difficulty in completing one or more ADL/IADL tasks. The logistic regression models were used to explore the association between HGS measures and functional disability. Results 11 950 (mean age 59.2 ± 9.6 years, 47.9% males) and 7540 (mean age 57.5 ± 8.6 years, 50.1% males) participants were included in the cross-sectional and prospective study, respectively. HGS asymmetry and weakness, individually or simultaneously, were associated with an increased prevalence of functional disability. During the four-year follow-up, 1822 (24.2%) participants had incident functional disability. The separate exposure to HGS asymmetry (odds ratio (OR) = 1.18; 95% confidence interval (CI) = 1.05–1.32) or weakness (OR = 1.59; 95% CI = 1.30–1.95) was independently associated with functional disability. For combined associations, those with both weakness and asymmetry showed the greatest risk of new-onset functional disability (OR = 1.91; 95% CI = 1.45–2.52). Conclusions HGS asymmetry and weakness were associated with a higher risk of functional disability. Assessing HGS asymmetry together with weakness may help to better identify those at risk of functional disability to enable early interventions.


and older adults in China
Online Supplementary Documents Table S1 Functional dependency by interval-of-need dependency categorization.
Table S2 Baseline characteristics of 11950 participants by the combined HGS weakness and asymmetry categories in the cross-sectional analysis.
Table S3 Baseline characteristics of 7540 participants without functional disability by HGS status in the prospective analysis.
Table S4 Baseline characteristics of 7540 participants without functional disability by the combined HGS weakness and asymmetry categories in the prospective analysis.
Table S5 Cross-sectional association between HGS status and functional disability in subpopulations of 5288 participants with complete data.
Table S6 Cross-sectional association between HGS status and functional disability, with HGS asymmetry defined by 20% and 30% rule.
Table S7 Cross-sectional association between HGS status and disability scores.
Table S8 Cross-sectional association between HGS status and functional dependency in subpopulations of 5288 participants with complete data.
Table S9 Cross-sectional association between HGS status and functional dependency, with HGS asymmetry defined by 20% and 30% rule.
Table S10 Longitudinal association of HGS status with functional disability in subpopulations of 3452 participants with complete data.
Table S11 Longitudinal association between HGS status and functional disability, with HGS asymmetry defined by 20% and 30% rule.
Table S12 Longitudinal association of HGS status with disability scores.
Table S13 Longitudinal association between HGS status and functional dependency in subpopulations of 3452 participants with complete data.
Table S14 Longitudinal association between HGS status and functional dependency, with HGS asymmetry defined by 20% and 30% rule.

Figure
Figure S1 Subgroup analyses for the longitudinal associations of HGS status with functional disability.

Figure
Figure S2Subgroup analyses for the longitudinal association of HGS status with functional dependency.

Table S2 .
Baseline characteristics of 11950 participants by the combined HGS weakness and asymmetry categories in the cross-sectional analysis

Table S3 .
Baseline characteristics of 7540 participants without functional disability by HGS status in the prospective analysis

Table S4 .
Baseline characteristics of 7540 participants without functional disability by the combined HGS weakness and asymmetry categories in the prospective analysis HGS -handgrip strength, BMI -body mass index, SD -standard deviation, IQR -interquartile range.*Missing data: 25 for BMI, 2902 for household income, 82 for occupation, 36 for social activities, 1 for smoking, 395 for drinking, 165 for multimorbidity, 1 for visual problems, 4 for hearing problems, 57 for depression score, and 1449 for cognitive function.

Table S5 .
Cross-sectional association between HGS status and functional disability in subpopulations of 5288 participants with complete data HGS -handgrip strength, ADL -activities of daily living, IADL -instrumental activities of daily living, OR -odds ratio, CI -confidence interval.Model 1: crude model; Model 2: adjusted for age and sex; Model 3: adjusted as model 2 plus marital status, educational level, residence, household income, occupation, social activities, smoking, drinking, multimorbidity, visual and hearing problems, depression score, cognitive function, and BMI.*

Table S6
Cross-sectional association between HGS status and functional disability, with HGS asymmetry defined by 20% and 30% rule ADL -activities of daily living, IADL -instrumental activities of daily living, OR -odds ratio, CI -confidence interval.Model 1: crude model; Model 2: adjusted for age and sex; Model 3: adjusted as model 2 plus marital status, educational level, residence, household income, occupation, social activities, smoking, drinking, multimorbidity, visual and hearing problems, depression score, cognitive function, and BMI.

Table S7 .
Cross-sectional association between HGS status and disability scores HGS -handgrip strength, ADL -activities of daily living, IADL -instrumental activities of daily living, CI -confidence interval.Model 1: crude model; Model 2: adjusted for age and sex; Model 3: adjusted as model 2 plus marital status, educational level, residence, household income, occupation, social activities, smoking, drinking, multimorbidity, visual and hearing problems, depression score, cognitive function, and BMI.*

Table S8 .
Cross-sectional association between HGS status and functional dependency in subpopulations of 5288 participants with complete data HGS -handgrip strength, OR -odds ratio, CI -confidence interval.Adjusted for age, sex, marital status, educational level, residence, household income, occupation, social activities, smoking, drinking, multimorbidity, visual and hearing problems, depression score, cognitive function, and BMI.*

Table S9 .
Cross-sectional association between HGS status and functional dependency, with HGS asymmetry defined by 20% and 30% rule

Table S10 .
Longitudinal association of HGS status with functional disability in subpopulations of 3452 participants with complete data

Table S11 .
Longitudinal association between HGS status and functional disability, with HGS asymmetry defined by 20% and 30% rule

Table S12 .
Longitudinal association of HGS status with disability scores

Table S13 .
Longitudinal association between HGS status and functional dependency in subpopulations of 3452 participants with complete data HGS -handgrip strength, OR -odds ratio, CI -confidence interval.Adjusted for age, sex, marital status, educational level, residence, household income, occupation, social activities, smoking, drinking, multimorbidity, visual and hearing problems, depression score, cognitive function, BMI, and follow-up time.

Table S14 .
Longitudinal association between HGS status and functional dependency, with HGS asymmetry defined by 20% and 30% rule HGS -handgrip strength, OR -odds ratio, CI -confidence interval, NA -not available due to limited sample sizes.Adjusted for age, sex, marital status, educational level, residence, household income, occupation, social activities, smoking, drinking, multimorbidity, visual and hearing problems, depression score, cognitive function, BMI, and follow-up time.